1. Field
This invention is concerned generally with the field of immobilized proteins and specifically with enzymes and immune bodies which have been immobilized on inorganic support materials.
2. Prior Art
The desirability of immobilizing enzymes, antibodies, and other proteins for repetitive use and/or ease of handling is well known. Proteins have been immobilized or fixed on a wide variety of materials, both organic (e.g. U.S. Pat. No. 3,705,084 to Reynolds) and inorganic (e.g. U.S. Pat. No. 3,519,538 to Messing et al. disclosing enzymes bound via silanes and U.S. Pat. No. 3,652,761, to Weetall disclosing antibodies bound via silanes). See also, U.S. Pat. No. 3,850,751, to Messing disclosing enzymes bonded via adsorption to certain inorganics and U.S. Pat. No. 3,930,951 to Messing disclosing the use of another intermediate, 4,4'-bi (methoxybenzenediazonium chloride) or BMBD, to bond enzymes to various inorganics.
Although bonding by adsorption or via covalent bonds both have advantages and disadvantages relative to each other, it can be appreciated that, in general, bonding via chemical coupling means provides a stronger bond which is not subject to such factors as pH change. Hence, considerable attention has been directed toward finding relatively inexpensive "coupling agents" which can be used as intermediate links between proteins and various inorganic supports. Although substances known as silane coupling agents have been used as coupling agents for some time now, such materials are relatively expensive and must often be chemically modified after attachment to the inorgainic, but before reaction with the protein, thus adding an undesirable processing step and added cost. The BMBD compound disclosed recently in U.S. Pat. No. 3,930,951 offers some advantages over silane coupling agents but it is still rather expensive.
We have now found there exists an intermediate coupling agent which is relatively inexpensive and requires little or no modification prior to protein bonding. Details of our method of using such coupling agent to bond a variety of proteins are disclosed herein.